Kieserite

Kieserite, permitted as an organic nutrient source by the European Commission Regulation, is an earth mineral mined from naturally occurring marine deposits. Chemically known as magnesium sulphate monohydrate, it provides soluble sources of both Magnesium and Sulphur for plant nutrition, and is not effected by, or effects, soil ph. Essential for healthy leaves and photosynthesis, a deficiency in magnesium is common in tomatoes, apples, grape vines, raspberries, roses and rhododendrons.